From: James Prestwood <prestwoj@gmail.com>
To: Denis Kenzior <denkenz@gmail.com>,
Simonas Kazlauskas <iwd.lists.linux.dev@kazlauskas.me>
Cc: iwd@lists.linux.dev
Subject: Re: Is the data rate estimation for 5GHz channels overly pessimistic?
Date: Tue, 24 Oct 2023 08:40:56 -0700 [thread overview]
Message-ID: <71f5cd1f-ea9d-4e47-bc4b-eeb0a1ceb310@gmail.com> (raw)
In-Reply-To: <1740def7-87b2-4d14-a6b1-c4522b9dcbf1@gmail.com>
On 10/24/23 8:32 AM, Denis Kenzior wrote:
> Hi James,
>
>>>
>>> They are not made up, they're direct from 802.11. But again, they're
>>> the _minimum_ specified sensitivity. Hardware typically does better.
>>
>> The rates/MCS table (ht_vht_rates) is from 802.11, but the mapping
>> from RSSI to MCS index's (ht_vht_he_base_rssi) is not. The spec just
>> has a formula for calculating the rate using a given MCS/channel
>> width. IWD just chooses what it thinks the MCS will be for a given RSSI.
>
> Sheesh! Everything is directly from 802.11.
>
> 80211-2020.pdf, page 2835, Table 17-18.
> 80211ax-2021.pdf, page 642, Table 27-51
Apparently wherever I got them from, got them from the spec. IIRC I
couldn't find such tables when I was doing this, and found something
online. Hence why I left this comment:
* Note: The values here are not based on anything from 802.11 but data
* found elsewhere online (presumably from testing, we hope). The two
* indexes for HE (MCS 11/12) are not based on any data, but just
* increased by 3dB compared to the previous value. We consider
this good
* enough for its purpose to estimate the date rate for network/BSS
* preference.
I suppose this can be removed now since they did in fact come from the spec.
>
>>
>> I don't remember exactly where I got those values from but this seems
>> to match:
>>
>
> The spec?
>
> Regards,
> -Denis
next prev parent reply other threads:[~2023-10-24 15:40 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-10-14 9:23 Is the data rate estimation for 5GHz channels overly pessimistic? Simonas Kazlauskas
2023-10-14 16:02 ` James Prestwood
2023-10-14 17:36 ` Denis Kenzior
2023-10-14 17:45 ` Simonas Kazlauskas
2023-10-14 18:07 ` Denis Kenzior
2023-10-15 19:40 ` Simonas Kazlauskas
2023-10-16 11:35 ` James Prestwood
2023-10-16 12:38 ` James Prestwood
2023-10-16 19:12 ` Denis Kenzior
2023-10-16 20:20 ` Simonas Kazlauskas
2023-10-21 23:23 ` Simonas Kazlauskas
2023-10-22 20:14 ` Denis Kenzior
2023-10-24 12:32 ` James Prestwood
2023-10-24 14:26 ` Denis Kenzior
2023-10-24 15:06 ` James Prestwood
2023-10-24 15:32 ` Denis Kenzior
2023-10-24 15:40 ` James Prestwood [this message]
2023-10-24 15:19 ` Simonas Kazlauskas
2023-10-24 15:29 ` Denis Kenzior
2023-10-16 18:36 ` Denis Kenzior
2023-10-14 17:42 ` Simonas Kazlauskas
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